Plate tectonics: the theory explaining how the earth's continents move
Continental drift: he gradual movement of the
continents across the earth's surface through geological
time.
continents across the earth's surface through geological
time.
Pangaea: a hypothetical continent including all the landmass of the earth.
Asthenospere: the upper layer of the earth's mantle, below the lithosphere
Lithosphere : the rigid outer part of the earth, consisting of the crust and upper mantle.
Mid-Oceanic ridge: a long, seismically active submarine ridge system situated in the middle of an ocean basin and marking the site of the upwelling of magma associated with seafloor spreading.
Rift valleys: a large elongated depression with steep walls formed by the downward displacement of a block of the earth's surface between nearly parallel faults or fault systems.
Subduction:
the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.
the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate.